I have inherited a firewall I'm struggling to find tutorials on. I have a situation that requires the ip address for the owner of the company to have unrestricted access through the firewall. I'm certain I'm not using the correct search terms on my google searches. I'm trying to work my way through the cisco documentation to answer the question, but no success.

Yes of course you can do this with ASDM. You would likely need to make a static NAT assignment mapping the outside interface address to the internal one and then make an access rule (access-list) that allows whatever kind of access "the boss" requires. Poking a hole in a firewall like this is almost always a bad idea as fire can then get in through the hole.

Working with a device you are not familiar with when it is something as important as a firewall is also a bad idea as just one little mistake could make it so that it is no longer an effective firewall -- I once audited a firewall that had a permit any to any rule left over from Cisco TAC instructing someone they were guiding in setting up a VPN tunnel to do that just temporarily so that they would know the traffic wasn't getting stopped by any access list; of course they forgot to tell the person to remove it when they were finished and got the tunnel working and it was still there years later when I was called into the situation to find out why their firewall was acting like it wasn't even there :) Effectively it wasn't a firewall any longer and the organization had suffered numerous security breaches as a result of this one simple mistake.

Yes, you can do this from the GUI. However, it is not just point-and-click on the ASA. Look for tutorials for creating a remote access VPN on the ASA via ASDM. There are also some CLI tutorials out there that you could check out.

Another option might be to set them up with a remote access client on a workstation that they can access from their computer at home.